System and method for ultrasound imaging
Embodiments presented herein describe a method, a system and a computer program product for ultrasound imaging. The method in one example includes receiving a plurality of ultrasound echo signals from a plurality of transducer elements in response to ultrasound transmit beams. The method computes beam sums of ultrasound echo signals originating from a point to be imaged, for the corresponding ultrasound transmit beams. The method generates a time record comprising a plurality of beam sums, wherein the time record includes beam sums corresponding to multiple instants of time in a time window. The method filters the time record based, at least in part, on a predetermined response function. Finally, the method reconstructs the point to be imaged based on one or more of the filtered time records corresponding to one or more of the plurality of ultrasound transmit beams. The method repeats this process for each point to be imaged.
1. A system for ultrasound imaging, comprising:
an analog to digital converter for digitizing ultrasound echo signals from a plurality of transducer elements in response to ultrasound transmit beams;
a matched filter for filtering the digitized ultrasound echo signals;
a first buffer for storing the ultrasound echo signals;
a beamformer for computing beam sums of the ultrasound echo signals, wherein the beamformer is focused at a point to be imaged,
a second buffer for storing into a time record a plurality of said beam sums corresponding to multiple instants of time in a time window;
a second filter for filtering the time record based, at least in part, on a predetermined response function; and
a processor to reconstruct a set of image samples, the processor performing the following for at least a portion of the set of image samples:
computing a coherent sum of at least one of the beam sums in the filtered time record; and
demodulating the coherent sum to form an output image sample corresponding to the point to be imaged.
2. The system of claim 1 , wherein the matched filter utilizes a transmit impulse response, receive impulse response, transmit excitation applied to transducer elements or serial combinations thereof.
3. The system of claim 1 , wherein the matched filter is a bandpass filter centered around second or higher harmonic frequency of the ultrasound transmit beams.
4. The system of claim 1 , wherein the matched filter is a bandpass filter centered around a center frequency of the ultrasound transmit beams.
5. The system of claim 1 , wherein the predetermined response function comprises an expected ultrasound echo signal.
6. The system of claim 1 , wherein the matched filter comprises a single pulse matched filter for single pulse match filtering the time record based on the predetermined response function; and
the second filter comprises a RAKE Finite Impulse Response (FIR) filter for filtering the single pulse match filtered time record.
7. The system of claim 1 , wherein the predetermined response function comprises a RAKE Finite Impulse Response (FIR) or an approximated RAKE Finite Impulse Response (FIR).